How do I configure my firewall to allow email services.
The only truly reliable way is to build your system, enable your firewall, and then begin using your mail system in every conceivable way. When your firewall blocks something it should allow, adjust the rules and proceed. Within a day or two, you should be all set.
Can you be more specific?
Sort of. I can't tell you how to configure your firewall but I can tell you how I configure mine. I use IPFW that's built right into FreeBSD. Technically, I use IPFW2 but, that little fact is largely irrelevant. I configure /etc/rc.firewall and modify the client or simple section, depending on how the machine is configured on my network(s). Here are the parts of my firewall script that are relevant to Mail::Toaster:
I use the IFPW_DEFAULT_TO_ACCEPT kernel option and then implicity deny all packets at the end of my firewall ruleset. By doing so I can change my ipfw rules on the fly without worry of disconnecting my SSH connection to the server. (Yes, I know how to get around that, but that doesn't mean I always remember). So, I end up adding the following options to my kernel config file:
Last modified on 5/26/05.